U.S. patent application number 13/533805 was filed with the patent office on 2013-01-03 for esophageal stimulation devices and methods.
This patent application is currently assigned to E-Motion Medical, Ltd.. Invention is credited to Amichay Haim Gross, Dvir Keren, Michael Gabriel Tal.
Application Number | 20130006323 13/533805 |
Document ID | / |
Family ID | 46727263 |
Filed Date | 2013-01-03 |
United States Patent
Application |
20130006323 |
Kind Code |
A1 |
Tal; Michael Gabriel ; et
al. |
January 3, 2013 |
ESOPHAGEAL STIMULATION DEVICES AND METHODS
Abstract
Systems for stimulating one or more esophageal muscle
contractions are provided. The systems, which are designed to evoke
esophageal motion to promote the downward movement of material,
include an elongated member for placement in a patient's esophagus
and at least one mechanical or electrical stimulator coupled to the
elongated member. Methods for stimulating and contracting an
esophageal muscle using electrodes and a generated signal sequence
are also provided.
Inventors: |
Tal; Michael Gabriel;
(Savyon, IL) ; Keren; Dvir; (Tel Aviv, IL)
; Gross; Amichay Haim; (Herzliya, IL) |
Assignee: |
E-Motion Medical, Ltd.
Herzliya
IL
|
Family ID: |
46727263 |
Appl. No.: |
13/533805 |
Filed: |
June 26, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61501338 |
Jun 27, 2011 |
|
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|
61612072 |
Mar 16, 2012 |
|
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Current U.S.
Class: |
607/40 |
Current CPC
Class: |
A61N 1/36007 20130101;
A61N 1/0517 20130101 |
Class at
Publication: |
607/40 |
International
Class: |
A61N 1/372 20060101
A61N001/372 |
Claims
1-39. (canceled)
40. A method for generating esophageal motion, the method
comprising: positioning at least two electrodes, including a
proximally positioned electrode and a distally positioned
electrode, at spaced positions along the esophagus between the
upper esophageal sphincter and the lower esophageal sphincter;
electrically connecting the at least two electrodes to a generator;
and generating a signal sequence, including a first signal at the
proximally positioned electrode to stimulate a proximal esophageal
tissue and a second signal at the distally positioned electrode to
stimulate a distal esophageal tissue.
41. The method of claim 40, wherein the signal sequence produces a
contraction wave that travels a length of the esophagus.
42. A method for stimulating an esophageal muscle to evoke one or
more contractions within the esophagus, the method comprising:
positioning in the esophagus an esophageal stimulation device
comprising an intubation tube and a plurality of electrodes;
electrically connecting at least a first of the plurality of
electrodes to a grounding site; electrically connecting at least a
second of the plurality of electrodes to a signal generator; and
providing a signal sequence to at least the second of the plurality
of electrodes, wherein the signal sequence comprises a sequence of
pulse groups, wherein the time between at least some pulses in each
pulse group is less than the time between at least some pulse
groups.
43. The method of claim 42, wherein at least some of the pulses in
a pulse group have a voltage greater than a stimulating threshold
voltage.
44. The method of claim 42, wherein the signal sequence further
comprises one or more conditioning pulses below a stimulating
threshold.
45. A method for generating esophageal motion comprising: placing
in an esophagus an elongated member sized and configured for nasal
or oral placement into the esophagus and a series of stimulators
mounted or mountable on the elongated member, the stimulators
positioned to stimulate a series of spaced apart portions of the
esophagus; and generating at least one stimulating signal to evoke
at least one local esophageal contraction to promote a distally
traveling wave.
46. The method of claim 45 wherein at least one of the local
esophageal contractions is a spasm.
47-50. (canceled)
51. The method of claim 45, wherein at least one of the local
esophageal contractions substantially closes a local segment of the
esophagus lumen.
52. The method of claim 45, wherein at least one of the local
esophageal contractions decreases a local segment of the esophagus
lumen to at least 50% its initial diameter.
53. The method of claim 45, wherein at least one of the local
esophageal contractions develops a local esophageal pressure of at
least 15 mmHg.
54. The method of claim 45, wherein at least one of the local
esophageal contractions develops a local esophageal pressure of at
least 25 mmHg.
55. The method of claim 45, wherein the at least one local
esophageal contraction is produced in a patterned motion and
includes at least two evoked contractions at different esophageal
portions.
56. The method of claim 55, wherein the different esophageal
portions include adjacent esophageal portions.
57. The method of claim 55, wherein the different esophageal
portions include remote esophageal portions.
58. The method of claim 55, wherein the at least two evoked
contractions are sequentially and/or timely generated according to
a preset sequence.
59. The method of claim 45, wherein the distally traveling wave
includes peristalsis.
60. The method of claim 45, wherein the at least one stimulating
signal is generated by a generator sized and configured for
prolonged intra-oral or intra-esophageal placement.
61. The method of claim 45, wherein the elongated member is a
medical intubation device.
62. The method of claim 61, wherein the series of stimulators are
spaced along the effective length of the medical intubation
device.
63. The method of claim 61, wherein the medical intubation device
is a gastric feeding tube.
64. The method of claim 45, wherein at least one of the stimulators
includes an electrode.
65. The method of claim 45, wherein at least one of the stimulators
is fixed to the elongated member.
66. The method of claim 45, wherein the elongated member includes
at least one sensor mounted or mountable on the elongated
member.
67. The method of claim 66, wherein at least one sensor is mounted
on the elongated member distally to a distal-most stimulator.
68. The method of claim 66, wherein a proximal-most sensor is
positioned on the elongated member at least 5 cm distally to the
distal-most stimulator.
69. The method of claim 66, wherein the at least one sensor
comprises at least one of: a pH sensor, a pressure sensor, a
manometer, an impedance sensor, a motion sensor, a capacitance
sensor, and a mechanical sensor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/501,338, filed Jun. 27, 2011, and U.S.
Provisional Patent Application No. 61/612,072, filed Mar. 16, 2012,
both entitled "ESOPHAGEAL STIMULATION DEVICE", the disclosures of
which are fully incorporated herein by reference as if fully set
forth herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention, in some embodiments thereof, relates
to devices and methods for generating motility in GI organs, and in
particular to devices and methods for generating esophageal
motility for diminishing retrograde flow of gastric contents.
[0004] 2. Description of the Related Art
[0005] The esophagus is a tubular muscular organ having a length of
approximately 25 cm, located between the upper esophageal sphincter
(UES) and the lower esophageal sphincter (LES). The esophagus
functions solely to deliver food from the mouth to the stomach
using peristaltic muscle motion. Peristalsis is a sequential,
coordinated contraction wave that travels the entire length of the
esophagus, propelling intraluminal contents distally to the
stomach. Primary peristalsis is the peristaltic wave triggered by
the swallowing center. The peristaltic contraction wave travels at
a speed of approximately 2 cm/s and correlates with
manometry-recorded contractions. The secondary peristaltic wave is
induced by esophageal distension from the retained bolus, refluxed
material, or swallowed air, with the primary role to clear the
esophagus of retained food or any gastroesophageal refluxate.
Tertiary contractions are simultaneous, isolated, dysfunctional
contractions. Anesthetization or sedation are suspected of causing
suspension of esophageal peristaltic motility and lowers LES
pressure, hence gastric content are more prone to infiltrate and
travel proximally in the esophagus.
[0006] Gastric contents refluxing through the esophagus are known
to affect conditions which may increase morbidity and mortality
rates. Gastroesophageal Reflux (GER) is a condition, in which the
LES opens spontaneously, for varying periods of time, or does not
close properly and stomach contents rise up into the esophagus. In
Laryngopharyngeal Reflux (LPR), the retrograde flow of gastric
contents reaches the upper aero-digestive tract. In order to
diminish and treat such conditions, efforts have been made to
develop medical and surgical means for improving LES functionality
and for creating a substitute sphincter proximally adjacent the
stomach. In some occasions it may be advantageous to develop a
second "line of defense" provided proximally to the LES along the
esophagus, especially to push back any gastric contents or chyme
that infiltrated the LES or any substitute or supplement thereof.
Such a need may arise, for example, in cases of intubation and/or
ventilation, usually in anesthetized ICU patients, CVA patients, or
others, in which esophageal motility is muted or less dominant.
[0007] Tubefeeding (e.g., "gastric feeding" or "enteral feeding")
is a common and life preserving procedure, however complications
can arise. GER is commonly associated with tubefeeding, including
in usage of nasogastric tubing (NGT) and other gastric feeding
practices. Research in past years has discussed the emergence of
GER as an effect of the use of NGT (see for example in Ibanez et
al., "Gastroesophageal reflux in intubated patients receiving
enteral nutrition: effect of supine and semirecumbent positions",
JPEN J Parenter Enteral Nutr. 1992 September-October; 16(5):419-22;
in Manning et al., "Nasogastric intubation causes gastroesophageal
reflux in patients undergoing elective laparotomy", Surgery. 2001
November; 130(5):788-91; and in Lee et al., "Changes in
gastroesophageal reflux in patients with nasogastric tube followed
by percutaneous endoscopic gastrostomy", J Formos Med Assoc. 2011
February; 110(2):115-9).
[0008] Pulmonary aspiration is the entry of material from the
oropharynx or gastrointestinal tract into the larynx and lower
respiratory tract. Consequences of pulmonary aspiration range from
no injury at all, to chemical pneumonitis or pneumonia, to death
within minutes from asphyxiation. One common cause of pulmonary
aspiration is aspiration of gastric contents, as suggested in
relevant literature (see for example Pellegrini et al.,
"Gastroesophageal reflux and pulmonary aspiration: incidence,
functional abnormality, and results of surgical therapy", Surgery.
1979 July; 86(1):110-9, indicating that incidence of aspiration is
due to a motor disorder that interferes with the ability of the
esophagus to clear refluxed acid, and that abnormal pulmonary
symptoms can induce or result from gastroesophageal reflux).
[0009] Ventilator-associated pneumonia (VAP) is pneumonia that
develops 48 hours or longer after mechanical ventilation is given
by means of an endotracheal tube or tracheostomy. VAP results from
the invasion of microorganisms into the lower respiratory tract and
lung parenchyma. Intubation compromises the integrity of the
oropharynx and trachea and allows oral and gastric secretions to
enter the lower airways. The aetiopathogenesis of VAP requires
abnormal oropharyngeal and gastric colonization and the further
aspiration of their contents to the lower airways. Known risk
factors for gastric colonization include: alterations in gastric
juice secretion; alkalinization of gastric contents; administration
of enteral nutrition; administration of antacids; and the presence
of bilirubin. According to Torres et al. (in "Stomach as a source
of colonization of the respiratory tract during mechanical
ventilation: association with ventilator-associated pneumonia", Eur
Respir J. 1996 August; 9(8):1729-35), although the role of the
colonized gastric reservoir in the development of VAP remains
debatable, there is major evidence in the literature in favor of
the gastric origin of part of these pulmonary infections.
[0010] US Patent Application No. 2011/0130650 relates to an enteral
feeding device comprising "expandable means which prevents or
significantly reduces aspirations from the alimentary tract to the
respiratory system. In further aspects, the invention relates to
systems comprising said enteral feeding device, methods and uses
thereof" US Patent Application No. 2010/0160996 "relates to methods
and apparatuses for treating ailments by "inserting a
balloon-electrode device into an esophagus of a mammal, the
balloon-electrode device including: (i) a nasogastral (NG) tube
having an internal passageway and an external surface, (ii) at
least one electrode coupled to the external surface of the NG tube,
(iii) a conductor extending through the internal passageway of the
NG tube and electrically connecting to the electrode, and (iv) a
balloon surrounding the electrode and a portion of the NG tube;
inflating the balloon with fluid such that the electrode is
substantially centrally located within an interior volume of the
balloon; and applying at least one electrical signal to the
electrode via the conductor such that an electromagnetic field
emanates from the electrode to at least one of nerves and muscles
of the mammal."
[0011] US Patent Application No. 2008/0249507 relates to a "food
administering apparatus including a feeding tube, having a distal
outlet and proximal inlet, adapted for insertion of the distal
outlet into the stomach of an adult patient while the proximal
inlet is outside the patient, the tube being suitable for
administering food or medicine from a proximal port to the distal
outlet and at least one electrode mounted on the tube."
SUMMARY
[0012] According to an aspect of some embodiments of the present
invention, there is provided a system for evoking esophageal
motion. In some embodiments, the esophageal motion includes at
least one local contraction. In some such embodiments, at least one
local contraction decreases a local segment of the esophagus lumen,
optionally to at least 50% its initial diameter. In another
embodiment, the at least one local contraction fully closes a local
segment of the esophagus. In some embodiments, at least one local
contraction develops a local esophageal pressure of at least 15
mmHg, and optionally at least 25 mmHg, or higher, or lower or
intermediate to said values.
[0013] In some embodiments, the esophageal motion is a patterned
motion including at least two evoked contractions at different
esophageal portions. Optionally, the different esophageal portions
include adjacent esophageal portions and/or remote esophageal
portions. In some embodiments, the at least two evoked contractions
are sequentially and/or timely generated according to a preset
sequence. In some embodiments, the esophageal motion includes a
distally advancing contraction wave, optionally though not
necessarily including peristalsis. In some embodiments, use of such
a system and/or method of esophageal stimulation diminishes
retrograde flow of stomach contents. In some cases, such a method
accomplishes this result by stimulating the esophagus to produce a
distally travelling wave of contractions that simulate natural
peristalsis.
[0014] In some embodiments, the system for evoking esophageal
motion includes an elongated member sized and configured for nasal
or oral placement in a patient's esophagus. In some embodiments,
the elongated member is a medical intubation device, and
optionally, a gastric feeding tube.
[0015] In some embodiments, the system further includes at least
one stimulator mounted or mountable on the elongated member,
adapted to stimulate a chosen portion of the esophagus to evoke a
local shaped contractive reaction. Optionally, the at least one
stimulator is fixed to the elongated member. In some embodiments,
alternatively or additionally, the at least one stimulator is
provided with a fixator configured for mounting the at least one
stimulator on a chosen external portion of the elongated member.
The fixator may be slidably movable along a length of the elongated
member, optionally restrainedly securable around the chosen
external portion of the elongated member, and/or optionally fixedly
lockable to the chosen external portion of the elongated member
thereby preventing sliding therealong.
[0016] In some embodiments, the at least one stimulator includes at
least two stimulators sequentially positioned along an esophageal
length; each stimulator is configured to stimulate a different
esophageal portion. Optionally, a plurality of stimulators is
provided along the effective length of the medical intubation
device. In some embodiments, a distance of less than 5 cm exists
between at least two of the stimulators, and a distance of greater
than 10 cm exists between a proximal most stimulator and a distal
most stimulator.
[0017] In some embodiments, the at least one stimulator includes an
electrode, or a plurality of electrodes, for allowing local
electrical stimulation(s) of muscle tissue and/or neural tissue,
adjacent and/or in direct contact. The electrode(s) may be shaped
as chosen or needed, as known in the relevant art, and may be, for
example, circular, rectangular, or ring shaped.
[0018] In some embodiments, the at least one stimulator includes an
expandable member, which is optionally a mechanical stimulator,
optionally inflatable, and sized and/or shaped when expanded to
radially stretch out an esophageal portion in a manner that evokes
a shaped contractive reaction distal to the esophageal portion.
[0019] In some embodiments, the system further includes a generator
connected to the at least one stimulator. The generator may be
provided outside the patient body or alternatively be sized and
configured for prolonged intra-oral or intra-esophageal placement.
The generator may be an electrical signal generator adapted to
generate electrical stimulations via at least one electrode or at
least two electrodes electrically connected thereto. Alternatively,
the generator may include a pump for cases of inflatable
stimulators. The generator may be a pulse generator and/or may be
able to generate different shaped signals, for example a step wave,
a sine wave, a saw-tooth wave, a variable width pulse or any
combination thereof. The generator may include or be connectable to
a power source, which may or may not comprise an element of the
system. In some embodiments, the power source may be sized and
configured for prolonged intra-oral or intra-esophageal
placement.
[0020] In some embodiments of the invention, the system further
includes at least one sensor mounted or mountable on the elongated
member. The at least one sensor may be mounted distally to a
distal-most stimulator. Optionally, a proximal-most sensor is
positioned at least 5 cm distally to the distal-most stimulator,
optionally at least 10 cm, optionally approximately 20 cm, or
higher, or lower, or intermediate to said values. In some
embodiments, the at least one sensor comprises at least one of: a
pH sensor, a pressure sensor, a manometer, an impedance sensor, a
motion sensor, a capacitance sensor and a mechanical sensor.
[0021] In some embodiments, the system for evoking esophageal
motion includes a catheter and a controller, wherein the catheter
and controller are configured for wired or wireless communication
with each other. The catheter includes a plurality of electrodes
and at least one pH sensor. In some embodiments, the controller is
configured and programmed to initiate an electrical stimulation via
at least one of the plurality of electrodes in response to at least
one pH sensor sensing a local pH less than 3. In use, the at least
one pH sensor of various embodiments senses local pH in real-time,
and at least one of the plurality of electrodes is stimulated upon
the at least one pH sensor sensing a local pH below 3 in real-time.
In some embodiments, the plurality of electrodes and the one or
more pH sensors are arranged such that upon a pH sensor sensing a
local pH less than 3, one or more electrodes positioned proximally
to the pH sensor are stimulated.
[0022] In an aspect of some embodiments, there is provided a method
for generating esophageal motion. In some embodiments, the method
comprises a step of positioning at least two electrodes, including
a proximally positioned electrode and a distally positioned
electrode, at distant portions along the esophagus. Optionally, the
method includes also a step of electrically connecting the at least
two electrodes to a generator. Optionally, the method further
includes a step of generating a signal sequence including a first
signal at the proximally positioned electrode thereby stimulating a
proximal esophageal tissue and a second signal at the distally
positioned electrode thereby stimulating a distal esophageal
tissue. In some embodiments, the signal sequence produces a
contraction wave that travels a length of the esophagus.
[0023] Optionally, additionally or alternatively, a method for
generating esophageal motion with the system will include a step of
placing in an esophagus the elongated member and at least one
electrode mountable thereon, and generating at least one
stimulating signal to evoke a local shaped contractive reaction.
The local shaped contractive reaction may be a spasm, a full
contraction, a partial contraction, a peristalsis or any
combination thereof.
[0024] A method for connecting at least one electrode to a gastric
tube pre-positioned in a patient's esophagus may include a step of
locating a target portion on the gastric tube at a chosen distance
from a proximal end thereof. Optionally, the method also includes a
step of providing an electrode fixator configured for fixedly
covering a portion of the gastric tube. Optionally, the electrode
fixator comprises at least one electrode electrically connectable
with a signal generator and locking means. Optionally, the method
also includes a step of positioning the electrode fixator over the
target portion. Optionally, the positioning includes sleeving the
electrode fixator over and along the gastric tube. (Hereinafter,
sleeving is defined as sliding a sleeve, sock, or other
tubular-shaped element, rigid or nonrigid, over, around, and along
an object, so as to at least partially encase said object.)
Optionally, the method also includes a step of applying the locking
means to fixedly lock the electrode fixator in place. In some
embodiments, the gastric tube may be partially withdrawn to expose
the target portion.
[0025] Unless otherwise defined, all technical and/or scientific
terms used herein have the same meaning as commonly understood by
one of ordinary skill in the art to which the invention pertains.
Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of
embodiments of the invention, exemplary methods and/or materials
are described below. In case of conflict, the patent specification,
including definitions, will control. In addition, the materials,
methods, and examples are illustrative only and are not intended to
be necessarily limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Some embodiments of the invention are herein described, by
way of example only, with reference to the accompanying drawings.
With specific reference now to the drawings in detail, it is
stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of various embodiments. In this
regard, the description taken with the drawings makes apparent to
those skilled in the art how embodiments of the invention may be
practiced. In the drawings:
[0027] FIG. 1A schematically illustrates an exemplary nasogastric
tube positioned in a patient's esophagus and including a plurality
of stimulators, in accordance with an embodiment of the present
invention;
[0028] FIG. 1B schematically illustrates an exemplary oral feeding
tube positioned in a patient's esophagus and including a mono-polar
stimulator, in accordance with an embodiment of the present
invention;
[0029] FIG. 1C schematically illustrates an exemplary feeding tube
positioned in a patient's esophagus and including a plurality of
stimulators and a sensor, in accordance with an embodiment of the
present invention;
[0030] FIGS. 2A-C schematically illustrate a partial cut view of a
contraction wave stimulating system provided in an esophagus, shown
at different operation stages, in accordance with some embodiments
of the present invention;
[0031] FIGS. 3A-D schematically illustrate a first exemplary
stimulation sequence and a correspondingly generated patterned
esophageal motion, in accordance with some embodiments of the
present invention;
[0032] FIGS. 4A-D schematically illustrate a second exemplary
stimulation sequence and a correspondingly generated patterned
esophageal motion, in accordance with some embodiments of the
present invention;
[0033] FIG. 5A schematically illustrates a top view of an exemplary
esophageal intubation tube provided with a plurality of terminals
comprising two electrodes each; an exemplary signal sequence from
each terminal is also illustrated, in accordance with some
embodiments of the present invention;
[0034] FIG. 5B schematically illustrates a top view of an exemplary
esophageal intubation tube provided with a plurality of terminals
comprising two electrodes each; an exemplary signal sequence from
each terminal is also illustrated, in accordance with some
embodiments;
[0035] FIG. 6 schematically illustrates a top view of an exemplary
esophageal intubation tube provided with a plurality of terminals
comprising three electrodes each, in accordance with some
embodiments of the present invention;
[0036] FIG. 7 schematically illustrates a top view of an exemplary
esophageal intubation tube that is provided with a plurality of
terminals comprising two electrodes each and is coupled to an array
of switches, in accordance with some embodiments of the present
invention;
[0037] FIG. 8 schematically illustrates a top view of an exemplary
esophageal intubation tube having a plurality of electrodes with
polarities modulating over time to create a stimulation sequence,
in accordance with some embodiments of the present invention;
[0038] FIG. 9 schematically illustrates a top view of an exemplary
esophageal intubation tube having a plurality of electrodes with
polarities modulating over time to create another stimulation
sequence, in accordance with some embodiments of the present
invention;
[0039] FIGS. 10A-B schematically illustrate a partial isometric
view and a partial top view of an exemplary NG tube provided with a
plurality of electrodes, in accordance with some embodiments of the
present invention;
[0040] FIGS. 11A-B schematically illustrate a partial top view of
an exemplary NG tube provided with a plurality of expandable
stimulators, before and after actuation, in accordance with some
embodiments of the present invention;
[0041] FIG. 12 schematically illustrates an exemplary NG tube
positioned in a patient's esophagus and provided with a fixedly
positioned stimulator fixator, in accordance with some embodiments
of the present invention;
[0042] FIGS. 13A-D schematically illustrate different exemplary
fixators, in accordance with some embodiments of the present
invention;
[0043] FIGS. 14A-B schematically illustrate an exemplary
stretchable sleeve-type fixator, in accordance with some
embodiments of the present invention;
[0044] FIG. 15 schematically illustrates an exemplary delivery
device for delivering fixators to a feeding tube, in accordance
with some embodiments of the present invention; and
[0045] FIG. 16 schematically illustrates a partial cut view of an
exemplary self-expandable electrode fixator partially emerging from
a delivery catheter, in accordance with some embodiments of the
present invention.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
[0046] The following preferred embodiments may be described in the
context of exemplary esophageal stimulation procedures for ease of
description and understanding. However, the invention is not
limited to the specifically described devices and methods, and may
be adapted to various clinical applications without departing from
the overall scope of the invention. For example, devices and
related methods including concepts described herein may be used for
stimulating other GI organs such as but not limited to the: stomach
wall, duodenum, jejunum, ileum, caecum, small intestine, colon,
large intestine, throat and gullet.
[0047] The present invention, in some embodiments thereof, relates
to devices and methods for generating motility in GI organs, and in
particular to devices and methods for generating, at least,
esophageal motility for diminishing retrograde flow of gastric
contents.
[0048] An aspect of some embodiments relates to a system for
generating a patterned esophageal motion. A patterned esophageal
motion may be any local or cross-esophageal muscular expansion or
contraction, or any combination thereof, evoked and/or orchestrated
following generated stimulation. The pattern may be a chosen shape
and/or magnitude of a local esophagus contraction and/or a distally
progressive contraction wave having chosen characteristics,
including but not limited to contraction force, wave travel
velocity and wave occurrence frequency. In some embodiments, the
patterned esophageal motion includes peristalsis, optionally
simulating a naturally occurring esophageal peristalsis or creating
a synthetic peristalsis based on an algorithmic sequence of
stimulations, and/or any combination of local contractions,
distally progressive contraction wave and/or selectively evoked
naturally occurring peristalsis at a patient's esophagus.
[0049] In some embodiments, the system includes at least one
stimulator adapted to stimulate a portion of the esophagus to evoke
a shaped contractive reaction. In some embodiments, the at least
one stimulator includes an expandable, optionally inflatable,
member, sized and/or shaped when expanded to radially stretch out
an esophageal portion in a manner that evokes a shaped contractive
reaction distal to the esophageal portion. An inflatable stimulator
may be connected to a pump, optionally hydraulic or pneumatic, and
may be selectively inflated or deflated according to a chosen
scheme, such as, for example, a predetermined and/or programmed
scheme, and optionally a scheme including pulsatory actuation.
[0050] Optionally, alternatively or additionally, the at least one
stimulator includes an electrode configured for electrical
stimulation of adjacent/contacting esophagus muscle tissue. A
stimulating electrode may be connectable or provided readily
connected with a generator, optionally a pulse generator,
configured to generate a chosen sequence of stimulations.
Optionally, alternatively or additionally, an internal power and/or
signal source may be provided with the system that is sized and
configured for intra-body (e.g., intra-orally) placement,
optionally in or adjacent the esophagus. In some other optional
embodiments, a power and/or signal source may be provided (e.g.,
worn) on the patient. In some exemplary embodiments, at least one
electrode and/or sensor is connected with such an internal power
source sized and configured for placement on a medical intubation
device (e.g., a feeding tube).
[0051] In some embodiments, the system includes a plurality of
stimulators provided at different relative locations within the
esophagus.
[0052] A local contraction of the esophagus, or any combination or
pattern of esophageal contractions may increase local and/or
average esophageal pressure. Optionally, alternatively or
additionally, stimulation is used to decrease local and/or average
volume entrapped along the esophagus lumen between the LES and the
UES thereby increasing local and/or average pressure. By increasing
the pressure at a local segment of the esophagus lumen, a
retrograded material or chyme may be forced to travel backward to a
distal lumen segment being less pressured, whereas by increasing
the average or overall pressure in the esophagus, a possible reflux
causing positive pressure difference between the stomach and the
esophagus may be diminished and even reversed, thereby diminishing
the possibility or volume of refluxed material or even preventing
reflux. In some embodiments, a local and/or average pressure caused
by a single evoked contraction or a series of evoked contractions
may be equal or higher than 15 mmHg, optionally equal or higher
than 25 mmHg, optionally equal or higher than 50 mmHg, and
optionally equal or higher than 100 mmHg, or lower, higher, or
intermediate to any of said values.
[0053] In some embodiments, the system further includes, is
provided with, or is connected to a medical intubation device that
is sized and configured for nasal or oral placement in a patient's
esophagus. In some embodiments, the medical intubation device is a
gastric feeding tube.
[0054] In some embodiments, at least one stimulator is fixed to the
medical intubation device. Optionally, alternatively or
additionally, at least one stimulator is provided with a fixator
configured for fixedly covering a portion of the medical intubation
device. The fixator may be slidably movable along a length of the
medical intubation device and/or may be restrainedly securable
around the portion of the medical intubation device. In some
embodiments, the fixator is fixedly lockable to the portion of the
medical intubation device thereby preventing sliding
therealong.
[0055] A fixator may be sleeved and/or otherwise coupled to the
medical intubation device after the latter has been partially or
fully withdrawn from a patient's esophagus or trachea.
Alternatively, a fixator may be mounted on to a medical intubation
device prior to initial placement in the patient. A proper location
of a fixator and/or stimulator may be achieved under imagery
guidance (e.g., x-ray). Optionally, alternatively or additionally,
means (e.g., recesses, indentations, etc.) are provided or created
on portions of the medical intubation device to allow controlled
positioning by engaging the fixator/stimulator thereto. In cases in
which the medical intubation device is kept in place within the
patient, means may be applied to distally advance a
fixator/stimulator along and over the medical intubation tube's
outer periphery to a chosen location, optionally under x-ray
monitoring.
[0056] In some embodiments, the at least one stimulator includes at
least two stimulators sequentially positioned along an esophageal
length, each stimulator being configured to stimulate a different
esophageal portion. Optionally, a plurality of stimulators is
provided along the effective length of the medical intubation
device.
[0057] In some embodiments wherein the at least one stimulator
comprises a plurality of electrodes, the electrodes are arranged in
groups referred to herein as terminals. In some embodiments, two
electrodes form a terminal. In some such embodiments, one electrode
is a positive electrode, which receives current from a signal
generator, and the other electrode is a negative electrode, which
is grounded. The distance between each terminal may be fixed or
variable, and the terminals are spaced such that the distance
between each terminal is greater than the distance between each
electrode within any given terminal. For example, the width of the
terminal (i.e., the distance between the electrodes of a terminal)
may be 5-10 mm, and optionally 8 mm. The distance between each
terminal may be 15-30 mm, optionally 20 mm, or optionally, below,
above, or intermediate to said values. In other embodiments having
two electrodes per terminal, the system also comprises an array of
controlled relays coupled to the electrodes. The array of
controlled relays may be configured to selectively transition each
electrode between a positively connected state, a grounded state,
and a disconnected state. In still other embodiments, three
electrodes form a terminal. In such embodiments, two of the
electrodes may be grounded, and the third electrode, which is
positioned between the two grounded electrodes, may be a positive
electrode connected to a signal generator. The electrodes are
positioned such that the positive electrode will close a circuit
with the two negative (grounded) electrodes of the same terminal.
Such a design may position the center of stimulation at the
location of the positive electrode.
[0058] In some embodiments, the system includes at least one
sensor. Optionally, the sensor is provided on the medical
intubation device distally to the at least one stimulator.
Optionally, the sensor is a pH sensor, optionally adapted to sense
a change (e.g., decrease) of local pH, for example due to the
presence of gastric contents proximally to the LES. Optionally,
alternatively or additionally, an impedance sensor may be used,
configured for sensing a change in impedance of tissues provided
between stimulators and/or electrodes, optionally correlative to a
reaction to gastric contents or other substances. Optionally,
alternatively or additionally, other sensor types may be used,
including but not limited to a pressure sensor, a manometer, a
moisture sensor, a temperature sensor, a motion sensor, a
capacitance sensor and a mechanical sensor.
[0059] In an aspect of some other embodiments, there is provided a
method for generating esophageal peristalsis in a patient intubated
with a gastric tube. In some embodiments, the method comprises at
least one of the following steps, optionally with no particular
order: [0060] 1. positioning at least two electrodes, including one
or more proximally positioned electrodes and one or more distally
positioned electrodes, at spaced positions along the gastric tube,
where the positions are selected such that after installation of
the gastric tube, the at least two electrodes will be between the
upper esophageal sphincter (UES) and the lower esophageal sphincter
(LES); [0061] 2. electrically connecting the at least two
electrodes to a generator; and/or [0062] 3. generating a signal
sequence including a first signal at the proximally positioned
electrode thereby stimulating a proximal esophageal tissue and a
second signal at the distally positioned electrode thereby
stimulating a distal esophageal tissue.
[0063] In some embodiments, the electrodes apply electrical current
in a series of one or more electrical trains (also referred to
herein as pulse groups), wherein each train is composed of a series
of cycles, and each cycle includes one pulse. Pulses within a train
or pulse group are characterized by an interpulse spacing, and
different pulse groups are separated by an intergroup spacing.
Generally, the interpulse spacing between pulses within a group or
train is less than the intergroup spacing between at least some
groups. Each electrical pulse has an amplitude; in preferred
embodiments, the amplitude is higher than a stimulating threshold,
wherein the stimulating threshold is the minimum voltage at which a
local contraction occurs when applied to a portion of the
esophagus. In some embodiments, the stimulating threshold is
between 5V and 20V, optionally between 8V and 10V or between 10V
and 15V; in other embodiments, the stimulating threshold may be
higher or lower than said values. Each pulse is provided for a
duration of time. In some embodiments, the pulse width (i.e., the
duration) is equal to or greater than 5 milliseconds, and
optionally, equal to or greater than 10 milliseconds. The applied
pulse is followed by a duration of lower current and/or no current.
Together, one pulse and one duration of low current compose a
cycle. In some embodiments, one cycle lasts 20 ms; in other
embodiments, one cycle lasts 15 ms, or optionally 30 ms, or less
than, greater than, or intermediate to said values. In some
embodiments, multiple cycles are provided successively such that
together the cycles form a train having a duration of one to two
seconds. In other embodiments, trains are provided that are longer
or shorter in duration. The train is then followed by a duration of
no current or low current produced by below-threshold voltages.
[0064] In some embodiments, the sequence of trains or other signal
sequence produces a contraction wave that travels a length of the
esophagus. In some embodiments, the contractions generate or
simulate natural peristalsis.
[0065] In some embodiments, before each train or pulse, one or more
below-threshold pulses are applied to the tissue to prime the
tissue and induce it to contract more firmly and efficiently and to
begin contracting at lower voltage stimulation levels. Optionally,
a preliminary, below-threshold train is applied before each
stimulating train or pulse. In some embodiments, a continuous
below-threshold train is applied to specific portions of the
esophagus to desensitize, and thereby avoid unneeded contractions
within, said portions. For example, the LES must be open in order
for material to pass from the esophagus into the stomach. In one
embodiment therefore, one or more electrodes may also be positioned
on the gastric tube such that after installation they are adjacent
the LES to provide a continuous below-threshold train which will be
applied to the LES to desensitize it so that it does not contract
when material arrives. Such electrode(s) may also be used to close
the LES if that is a desired response under some circumstances.
[0066] In an aspect of some embodiments, there is provided a method
for connecting at least one electrode to a gastric tube readily
positioned in a patient's esophagus. In some embodiments, the
method comprises at least one of the following steps, optionally
with no particular order: [0067] 1. locating a target portion on
the gastric tube at a chosen distance from a proximal end thereof;
[0068] 2. providing an electrode fixator configured for fixedly
covering a portion of the gastric tube, the electrode fixator
comprising at least one electrode electrically connectable with a
signal generator and locking means; [0069] 3. positioning the
electrode fixator over the target portion; and/or [0070] 4.
applying the locking means to fixedly lock the electrode fixator in
place.
[0071] In some embodiments, at least one of the steps includes the
use of internal and/or external imagery. Optionally, additionally
or alternatively, imaging guidance, optionally including x-ray
and/or RF sources, may be applied, for example, to locate the
electrode and change its position on the feeding tube while in the
patient. This may allow the clinician to keep the feeding tube tip
in appropriate position while adjusting the location of the
electrode.
[0072] In some embodiments of the invention, the fixator
positioning includes a step of: sleeving the electrode fixator over
and along the gastric tube. Optionally, the method further
comprises a step of: partially withdrawing the gastric tube to
expose the target portion.
[0073] Referring now to the drawings, FIG. 1A schematically
illustrates an exemplary system 10 comprising an elongated member
11 positioned in a patient's esophagus and including a plurality of
stimulators 12, in accordance with an embodiment. Elongated member
11 may be any plastic or elastic rod or tube sized to enter and be
pushed through the esophagus, preferably with no injury to adjacent
tissues. Elongated member may be a probe, a catheter and/or a
nasogastric tube (NGT), the latter is optionally used for injecting
food directly to a patient's stomach and/or pumping out chyme to
relieve excessive gastric pressure. Stimulators 12 may be any
mechanical, electrical or chemical local muscle or neural
stimulators. Four stimulators 12 are shown for illustrative
purposes, although any other number of stimulators may be provided.
In some exemplary embodiments, stimulators 12 are or include at
least one electrode. In some embodiments, each shown stimulator 12
represents a number of electrodes provided around a local periphery
of elongated member 11. In some embodiments, stimulators 12 are
provided in a sequential order, optionally having a constant or
selectively changeable distance therebetween. Optionally,
stimulators 12 comprise bi-polar electrodes so that pairs of
adjacent non-short-circuited electrodes can be used for closing an
electrical circuit and thereby stimulate an esophageal muscle
tissue in-contact and in-between the two electrodes. A generator
13, optionally an electrical signal generator, is shown connected
to stimulators 12 via elongated member 11, optionally over and
along its outer periphery or via a lumen thereof. To produce a
series of esophageal contractions in accordance with a chosen
scheme or logic, such as optionally simulating a naturally
occurring esophageal peristalsis, separate generator outputs may be
provided to separate electrodes or electrode groups 12. In some
advantageous embodiments, the spacing between electrodes or
electrode groups 12 is less than 5 cm, and the distance between the
most proximal electrode or electrode group 12 and most distal
electrode or electrode group 12 is at least 10 cm. This allows
sequential stimulation of the electrodes or electrode groups 12
along a significant portion of the esophagus between the UES and
the LES.
[0074] In FIG. 1B, an exemplary system 20 is schematically
illustrated comprising an oral feeding tube 21 positioned in a
patient's esophagus and including a mono-polar stimulator 22, in
accordance with an embodiment. Although it is commonly more safe
and convenient to place an esophageal intubation via a nasal
cavity, there might be circumstances (e.g., with infant patients)
where a tube is inserted via the oral cavity as suggested in this
figure. Mono-polar stimulator 22 is electrically connected to an
outside source or ground (shown in the figure as "(-)") and is
selectively capable of closing an electrical circuit with an
external electrode 23, optionally positioned on the patient's neck
skin. A single electrode may be used to stimulate a neutrally
sensitive region thereby evoking an esophageal contraction wave
from the stimulated region and downward, optionally to the LES or
the stomach interim. Optionally, alternatively or additionally, a
single electrode may be used for local muscle contraction in order
to serve as a barrier for refluxed gastric contents and/or for
decreasing overall esophagus volume and increasing esophageal
pressure.
[0075] In FIG. 1C, an exemplary system 30 is schematically
illustrated comprising a feeding tube 31 positioned in a patient's
esophagus and including a plurality of stimulators 32 and a sensor
33, in accordance with an embodiment. Feeding tube 31 may be used
to introduce partly digested food or fluids directly to the small
intestine (e.g., opened at the duodenum or at the jejunum). Sensor
33 may be a pH sensor, optionally positioned adjacent or proximal
to the LES or stomach entry. In the case of a substantially low pH,
such as in the presence of acid refluxed chyme, sensor 33
automatically signals and/or initiates the stimulations protocol
for electrodes 32 to force the gastric content to flow back towards
the stomach. In cases where no sensor is present, different
stimulation protocols may apply, for example continuous stimulation
regimes in which different electrodes are used sequentially to
stimulate local tissues at specific frequencies and magnitudes.
Optionally, alternatively or additionally, a local esophageal
contraction or spasm is evoked, for any chosen duration, to act as
a local physical barrier, thereby preventing or diminishing
refluxed substance from passing therethrough. Such a local
contraction/spasm may be singular or generated at different
occasions and/or portions of the esophagus.
[0076] Reference is now made to FIGS. 2A-C which schematically
illustrate a partial cut view of a contraction wave stimulating
system 35 provided in an esophagus, shown at different operation
stages, in accordance with some embodiments. As shown in FIG. 2A,
in one embodiment, a gastric content or chyme travels proximally
away from the stomach adjacent to a pH sensor 36 previously
deployed in the esophagus. Once a pH change is sensed, proximally
positioned stimulators 38 initiate a stimulation having a magnitude
and/or frequency adapted to evoke a distally advancing esophageal
contraction wave capable of pushing back the chyme. As shown in
FIGS. 2B and 2C, a contraction wave CW is created by adjacent
stimulators 38 and moves distally while pushing the chyme back
towards the stomach. Optionally, CW simulates a naturally occurring
esophageal peristalsis, although the motion may be different from
natural peristalsis in at least one factor, for example, in
magnitude, speed and/or frequency.
[0077] Reference is now made to FIGS. 3A-D which schematically
illustrate a first exemplary stimulation sequence 40 and a
correspondingly generated patterned esophageal motion, using a
stimulation system 60, in accordance with some embodiments. As
shown, system 60 includes a catheter 61 extending across a length
of the esophagus and a plurality of bi-polar stimulation electrode
pairs, including a proximal-most electrode 62, then electrode 63,
electrode 64 and electrode 65. In this embodiment, each electrode
encircles the catheter. Stimulation sequence or protocol 40
generates a combination of signals through different channels,
including a channel 42 adapted to stimulate an esophageal muscle
tissue provided between electrodes 62 and 63, a channel 44 adapted
to stimulate an esophageal muscle tissue provided between
electrodes 63 and 64, and a channel 46 adapted to stimulate an
esophageal muscle tissue provided between electrodes 64 and 65. As
shown, channel 42 stimulates the esophagus with voltage V at
duration .DELTA.T1.sub.1 thus evoking a local contraction
CNTR1.sub.1 at the same duration. Immediately following, channel 44
stimulates the esophagus with voltage V at duration .DELTA.T1.sub.2
thus evoking a second local contraction CNTR1.sub.2 at the same
duration. This is followed by stimulation through channel 46 with
voltage V at duration .DELTA.T1.sub.3, which evokes a third local
contraction CNTR1.sub.3 at the same duration.
[0078] FIGS. 4A-D schematically illustrate a second exemplary
stimulation sequence 50 and a correspondingly generated patterned
esophageal motion, still using stimulation system 60, in accordance
with some embodiments. This time two channels, 52 and 54, are shown
with corresponding stimulation durations .DELTA.T2.sub.1 and
.DELTA.T2.sub.3 that are overlapping at partial duration
.DELTA.T2.sub.2. This way, a traveling contraction wave simulates a
general peristaltic motion in which a first local contraction
CNTR2.sub.1 extends distally to become CNTR2.sub.2 and only
afterwards diminishes to leave a distal local contraction
CNTR2.sub.3.
[0079] FIG. 5A schematically illustrates an exemplary esophageal
intubation tube 200 provided with a plurality of terminals 210
comprising two electrodes each: a positive electrode 212 and a
negative (grounded) electrode 214, in accordance with some
embodiments. The electrodes are spaced such that the distance 218
between each terminal is greater than the distance 216 between each
electrode within any given terminal. As used in this application,
whenever a distance between electrodes is mentioned, the center to
center distance is being referred to. The electrodes 212 and 214 of
each terminal 210 are connected to a remote electrical signal
generator via electrical circuitry (not shown). A current or
voltage, optionally a pulsed current or voltage, is provided to the
positive electrode 212. An exemplary signal sequence 220 is also
illustrated in FIG. 5A. As shown, a train 222 of pulses 224 is
provided to each terminal 210. In some embodiments, the signal
sequence 220 is staggered in time such that distally-located
terminals receive stimulating trains 222 after more
proximally-located terminals. By providing a plurality of terminals
210 receiving staggered signal sequences, a wave of contractions,
optionally simulating peristalsis, may be generated. In this
example there are three "waves" of stimulations that progress down
the esophagus and a second wave starts only after the first wave is
finished (with no overlapping). A different approach is seen in
FIG. 5B, where a second wave 228 starting at the upper portion of
the esophagus begins before a first wave 226 of stimulations down
the esophagus is completed. In this implementation, there may be
two distant esophagus portions which contract at the same time.
This may increase overall peristalsis efficacy, while better
overcoming still retrograding material that managed to "infiltrate"
through distal contractions/waves.
[0080] Another exemplary esophageal intubation tube 250,
illustrated schematically in accordance with some embodiments, is
provided in FIG. 6. The esophageal intubation tube 250 is provided
with a plurality of terminals 260 comprising three electrodes each.
In some embodiments, each terminal includes one positive electrode
263 and two negative electrodes 261 and 262 on either side of the
positive electrode 263. With such a configuration, the positive
electrode 263 of a terminal is positioned far closer to the
negative electrodes 261 and 262 of the same terminal, at both
directions, than to any other negative electrodes (e.g., 264). Such
a configuration allows for a more controlled discharge of current
and a more controlled area of stimulation. In some embodiments, the
positive electrode 263 is located equidistant to both negative
electrodes 261 and 262 within a terminal 260, thereby centering
stimulations at the location of the positive electrode 263. The
same stimulation protocol of FIG. 5 can be used with the electrodes
of FIG. 6 where each terminal 260 has two grounded (or other low
potential) electrodes rather than one.
[0081] In FIG. 7, an exemplary esophageal intubation tube 230 is
schematically illustrated having a plurality of terminals 232
comprising two electrodes 234 each. In accordance with some
embodiments, the esophageal intubation tube 230 of FIG. 7 is
coupled to an array 240 of switches 242. In one embodiment, the
array 240 of switches 242 electrically connects each electrode 234
to a signal generator or a grounding source or leaves the electrode
234 disconnected. Each electrode 234 is configured to selectively
transition between each of the three states (connected to the
signal generator, connected to ground, and disconnected), as
directed by the array 240. By selectively transitioning the
electrodes between the various connected states, the area of
stimulation can be changed.
[0082] FIG. 8 schematically illustrates the polarity of various
electrodes 274 modulated over time, wherein the electrodes 274 are
positioned on an exemplary esophageal intubation tube 270, in
accordance with some embodiments. In the embodiment of FIG. 8, the
electrodes are arranged into terminals 272 at spaced positions
along the length of the esophageal intubation tube 270 between the
UES and the LES. Each electrode 274 on the esophageal intubation
tube 270 may be coupled to an array of switches (such as shown in
FIG. 7). With such an arrangement, the polarity of the electrodes
274 can be modulated over time, as directed by the array of
switches, to generate a sequence of voltage applications. One
potential sequence of voltage applications is provided in FIG. 8;
however, any sequence may be applied, and all such sequences are
contemplated herein. As depicted, all electrodes with "(+)" located
beside them are receiving a voltage from a signal generator; the
electrode having "(-)" beside it is grounded (or at another low
potential); and all electrodes without a symbol are disconnected
from the signal generator. The general area of stimulation at each
depicted time is represented by the drawn ellipses. As shown, the
area of stimulation may be controlled and changed over time. This
is one way to produce a distally traveling wave while controlling
the "length" of the stimulated portions. Here, the length is chosen
between proximal-most "+" and distal
[0083] Similarly, FIG. 9 schematically illustrates the polarity of
various electrodes 284 modulating over time, wherein the electrodes
284 are positioned on an exemplary esophageal intubation tube 280,
in accordance with some embodiments. FIG. 9 illustrates another
potential sequence of voltage applications provided to produce an
exemplary wave of distally-progressing contractions within the
esophagus. The degree of spatial overlapping between stimulations
need not be coherent. For example, in first change of polarity
there is substantial overlap, then small overlap, then substantial
overlap, etc.
[0084] Reference is now made to FIGS. 10A-B which schematically
illustrate a partial isometric view and a partial top view of an
exemplary stimulating system 70 comprising an NG tube 71 and a
plurality of electrodes 73 and 74, in accordance with some
embodiments. Electrodes 73 and 74 are connected to a remote
electrical signal generator (not shown) via electrical circuitry 75
provided over NG tube 71 or embedded in its wall. Electrodes 73 and
74 may fully or partially encircle the circumference of the tube
71. Opening 72 is provided at the lower end to deliver food and
other nutrients to the stomach.
[0085] An alternative stimulator system 80 is shown in FIGS. 11A-B,
which schematically illustrate a partial top view of system 80
comprising an NG tube 81 and a plurality of expandable stimulators
82 and 84, before and after actuation, in accordance with some
embodiments. In some exemplary embodiments, stimulators 82 and/or
84 are inflatable, and optionally toroidal shaped balloons, which
encircle portions of the NG tube 80. The distal expandable
stimulator 82 is optionally connectable to a remote pump (not
shown) via line 83, whereas the proximal stimulator 84 is
optionally connectable to the pump via line 85. Lines 83 and/or 85
may be hydraulic or pneumatic lines configured to provide
pressurized media from the pump into stimulators 82 and/or 84,
correspondingly. Optionally, the pumped medium is provided in a
pulsatory fashion. In FIG. 11B, stimulator 82 is shown in a
maximally expanded form. In some embodiments, stimulator 82 may
expand to a predetermined and/or limited shape and/or size, which
causes an esophageal tissue in contact to radially stretch open in
order to evoke a natural downward peristalsis, and optionally, to
simulate a spontaneous naturally occurring peristalsis.
[0086] In some instances it may be advantageous to add a
stimulating device over an existing intubation tube nested in a
patient's esophagus, as for example in a patient entering ICU with
an NGT in place. FIG. 12 schematically illustrates an exemplary
system 100 which comprises an NGT 110, positioned in a patient's
esophagus and provided with a fixedly positioned stimulator fixator
120, in accordance with some embodiments. The fixator 120 includes
at least one stimulator (e.g., a balloon type or electrode-type)
and is shown connected to a remote generator 130. The fixator 120
may be pushed along a length of the NGT 110 to a chosen distance or
esophagus portion. Optionally, alternatively or additionally, the
NGT 110 is partially withdrawn, optionally until a target NGT
portion is expelled from the body and/or is conveniently reachable
to place the fixator 120 thereto. The fixator 120 may be sleeved
along the NGT 110, or it may be a cuff-type fixator, deployable to
restrictively compress the at least one stimulator in place along
the NGT 110.
[0087] FIGS. 13A-D schematically illustrate different exemplary
fixators, in accordance with some embodiments. In FIG. 13A, an
elongated slitted sleeve 131 is shown, partially covering a
proximal portion of an NGT, including a plurality of electrodes 133
electrically connectable to a remote source (e.g., an electrical
signal generator) via a cord 134. The slitted sleeve 131 includes a
slit 132 across its entire length, thereby facilitating its
fixation to the NGT without a need to substantially widen it
before. In some embodiments, the slitted sleeve 131 is
self-contractible in a way that totally avoids movement along the
NGT once fixated thereto. FIG. 13B shows a different exemplary
embodiment in which electrodes are fixated to an NGT using distinct
cuff-like fixators: a distal electrode 142 is fixed to the NGT
using a fixator 141, and a proximal electrode 144 is fixed to the
NGT with a fixator 143. A cord 145 connects the electrodes to a
remote signal generator (not shown). FIGS. 13C and 13D show
transverse cross-sections of different cuff-like stimulator
fixators 150 and 155, correspondingly. The cuff-like fixator 150
includes a body 151, two opposing electrodes 152 connectable to a
remote generator by a cord 153. A locking means 154 is provided in
body 151 in the form of a snap-lock. When the locking means 154 is
opened, the fixator 150 allows slippage over a standard sized NGT,
and when locked it is restricted in place, and may optionally
slightly constrict the NGT portion it is confined to. The cable-tie
type fixator 155 similarly includes a body 156 housing two opposing
electrodes 157 connectable to a remote generator with a cord 158.
Unlike the fixator 150, the fixator 155 includes a cable-tie type
fastener 159 (comprising a gear-rack member and a ratchet member)
as the locking means, allowing an operator to adjust the tightness
of the fixator to adequately fixate the electrodes in place. In
some exemplary embodiments, the deformation of the NGT as a result
of the cuffing ensures a substantial grip and/or friction to
disable any movement of the cuff along the tube, while preferably
not restricting the NGT's inner lumen to a smaller diameter. In
some embodiments, the cuffing narrows the diameter of the NGT's
inner lumen by no more than 10% of its cross-section.
[0088] FIGS. 14A-B schematically illustrate an exemplary
stretchable sleeve-type fixator 160, in accordance with some
embodiments. The fixator 160 includes a stretchable tubular body
161 and a plurality of electrodes 162. In FIG. 14A, the fixator 160
is shown compressed and having an optional radially expanded form
which allows it to be easily sleeved about an NGT portion, whereas
in FIG. 14B, it is stretched open over most of the NGT portion and
confined from stretching further by the NGT's diameter. In some
embodiments, the fixator body 161 is braided from elastic fibers,
either polymeric and/or metallic. Optionally, the body 161 is
self-elongating. In some embodiments of the invention, an operator
(e.g., a medical staff member) pushes the compressed fixator 160
over the NGT until reaching a chosen position and then releases it
to stretch open in place. Optionally, the operator further
stretches the fixator 160 to plastically deform a portion thereof
and thereby further fixate it in place.
[0089] Reference is now made to FIG. 15 which schematically
illustrates an exemplary delivery device 170 for delivering
fixators, such as the cuff-like fixator 150, to a feeding tube (not
shown), in accordance with some embodiments of the present
invention. The delivery device 170 includes a handheld body 171 and
two opposing jaws 172 and 173, axially movable relative to each
other. A trigger 174 is manually operable to decrease a distance
between jaws 172 and 173 from a first wider distance, in which the
fixator 150 is maintained in an open state, to a second narrower
distance, in which the fixator 150 is forced to compress and lock.
Optionally, the first wider distance and/or the second narrower
distance are predetermined and/or programmable. In some
embodiments, the delivery device is configured to grab and fixate a
fixator in a sequential manner, whereas in other embodiments, the
delivery device may be housing a cartridge filled with fixators and
is applicable for stapling fixators in sequence until the cartridge
is emptied. The delivery device 170 may be reusable and may be
configured to allow for replacing singular fixators or fixator
cartridges. Alternatively, the delivery device 170 may be
configured for disposable single usage. The delivery device 170 may
include a mechanical, electrical and/or electromechanical mechanism
(not shown) to operate the stapling following triggering.
Optionally, the delivery device 170 includes a safety mechanism
(not shown).
[0090] A stimulator fixator may be deployed to radially expand
against the esophagus inner walls instead of compressing onto a
tube or being provided as a radially non-compliant member (e.g., a
probe or a catheter). FIG. 16 schematically illustrates a partial
cut view of an exemplary self-expandable electrode fixator 180
partially emerging from a delivery catheter 182, in accordance with
some embodiments of the present invention. As shown, fixator 180
includes a radially elastic body 181, self-expandable from a
smaller confined diameter to a final fully expanded diameter. A
plurality of electrodes 183 are fixated to body 181 in a manner
that does not damage its ability to expand as needed. Fixator body
181 is delivered in a confined smaller diameter in delivery
catheter 182 thereby allowing an easier advancing in the esophagus.
Once in place, catheter 182 may be withdrawn, leaving in place
fixator 180, and allowing it to gradually expand until complete
removal. In some embodiments, fixator body 181 is configured to
freely expand up to a diameter that is greater than the inner
diameter of the esophagus, therefore it is kept securely in place
by continuously applying expansive forces towards the surrounding
esophagus walls.
[0091] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims.
[0092] All publications, patents and patent applications mentioned
in this specification are herein incorporated in their entirety by
reference into the specification, to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated herein
by reference. In addition, citation or identification of any
reference in this application shall not be construed as an
admission that such reference constitutes prior art. To the extent
that section headings are used, they should not be construed as
necessarily limiting.
* * * * *